checked check radio button by jquery code example

Example 1: jQuery check a radio button

// jQuery version 1.6 or above use:  
$("#myRadioID").prop("checked", true);
 
//jQuery versions below 1.6 use:
$("#myRadioID").attr('checked', 'checked');

Example 2: How can I know which radio button is selected via jQuery

if ($('input[name="radioName"]:checked', '#myForm').length) {
	//Yes, it's checked!
}